Mineral oil composition



Patented July 9, 1946 MINERAL on. coMrosmoN Herschel G. Smith, Wallingford, and Troy L.

Cantrell Corporation, Pennsylvania Lansdowne, Pa.,

Pittsburgh, Pa., acorporation of assignors to Gulf Oil No Drawing. Application March 19, 1945, Serial No. 583,654

11 Claims.

This invention relates to mineral oil compositions. More particularly, the invention is concerned with mineral lubricating oil compositions of a character adapted to protect ferrous and other metal surfaces to which they are applied, from rusting and other types of corrosion in ad dition to affording lubrication of such surfaces.

Simple mineral oil films afford only a limited protection to metal surfaces from rust and other types of corrosion, but do not afiord any great protection under severe conditions of use. Many so-called anti-rust lubricating oils have been proposed, consisting of mineral oils and added constituents intended to protect metallic surfaces from rust, tarnish, or corrosion. Most of them are of rather limited applicability, in that while they afiord satisfactory protection to one class of metals, they may be ineffective, or even deleterious, with another class of metals.v

These shortcomings of such mineral oils and oil compositions are serious in many cases, particularly in cases wherein a plurality of metals must be simultaneously lubricated while exposed to corrosive conditions; for example, in the'case of copper-alloy bearings with steel shafting and the case of electric motors where surfaces of both steel and copper are exposed to corrosive conditions. Moreover, many such oils show undue sensitivity to moisture and air and other substances to which they are exposed and lubricating films of such oils do not effectively protect the metal against rusting or tarnishing when exposed to moisture and air or other corrosive atmospheres. It is also foundthat some compounded oils which are effective as regards preventing rust, are deficient in lubricating properties.

Among the objects of the present invention is the provision of an anti-corrosion lubricating oil composition, of good lubricating properties, adapted to protect steel from rusting whilebeing of itself free from tendency to corrode copper and other metallic surfaces, and being in itself relatively inert and unaffected by air and moisture.

These and other objects of the invention are achieved by the provision of a mineral oil composition, including as a rust inhibitor, the substantially neutral reaction products obtained by reacting primary fatty amines containing from 8 to 18 carbon atoms with acid phosphate esters of alkylated phenols containing at least one branched chain alkyl group, the said amines and acid phosphate esters being reacted in approximately equi-molecular proportions under such conditions that the reaction product or mixture has a pH value between 5.5 and 7.5.

We have found that such improved oil compositions are very effective as anti-corrosion lubricants for metal surfaces in general. They formtightly adherent oil films on the metal, protecting the metal surfaces from moisture and air. In addition, the improved oil composition itself is freefr'om any tendency to attack'copper, steel and other metals by reaction therewith or otherwise. For instance, polished or highly. finished steel surfaces protected by establishing and maintaining the improved oil composition on the surfaces thereof remain bright indefinitely and cop per alloy bearings (which present a difiicult problem in protection from corrosion) are maintained in-their highly finished condition even under unfavorable conditions of use. Further, copper, aluminum, zinc, silver, tin and their alloys are all effectively guarded against corrosion and are well lubricated by these improved oil compositlons containing our new rust inhibitors.

In general, various improved lubricants, such as household lubricants, machine oils, gun oils, turbine oils, slushing oils and the like are prepared, by selecting a suitable lubricating oil or base and dissolving the required amount of the above described reaction products in the oil.

In particular, the invention finds special utility in preparing improved oil compositions of the so-called household type, usefulfor lubricating light mechanisms such as electric motors, guns, etc., and containing relatively light (low viscosity) oils as the lubricating base. That is, the invention 'is especially well suited for improving highly refined lubricating oils having a Saybolt Universal viscosityranging from to- 150 at F.; mineral oils of 100 visoositybeing especially suitable for preparing our improved oil compositions.

In general, from 0.01 to 10.0 per cent of the inhibitor is suflicient to impart to lubricating oils adequate rust-inhibiting properties. More concentrated oily solutions or oil mixtures of the inhibitor can be prepared, as a stock solution or concentrate, which can be diluted with lubricating oil to form a rust-preventive lubricant. Usually 0.5 per cent or less of the inhibitor is sumcient to impart to mineral lubricating oils ade-' quate rust-inhibiting properties for metal articles exposed to moisture and air, but asmuch as 25 per cent by weight on the oil is sometimes in- .corporated toafford prolonged and complete protection from rust under extremely severe conditions, Such highly concentrated compositions .hibitors by reacting the acid 3 still retain excellent lubricating and other characteristics in addition to affording practically complete rust protection under extraordinary conditions.

The reaction products we employ are relatively stable compositions under ordinary conditions oils. Their solubility varies somewhat with the particular oil. For instance, light paramnic oils, such as these employed in making household lubricants, etc., dissolve approximately 50.0 per cent by weight of these reaction products, forming stable solutions thereof. Naphthenic type mineral oils dissolve somewhat larger amounts. In general, the solubility of these reaction products ,or inhibitors is quite high in most oils.

These advantageous rust inhibitors can be readily prepared from primary fatty amines containing from 8 to 18 carbon atoms and acid phosphate esters of alkylated phenols containing at least one branched chain alkyl group, by reacting said amines and acid phosphate esters together in approximately equimolecular ratios, as stated ante. In preparing our rust inhibitors or reaction products, the reaction is controlled so as to produce substantially neutral reaction products or mixtures having a pH value within the range 5.5 to 7.5 (as measured with quinhydronecalomel electrode assembly).

The primary fatty amines employed as one reactant are mono-alkyl amines having the follow ing formula:

H-N-H i wherein R represents an alkyl group containing from 8 to 18 carbon atoms. For the present purposes, the primary fatty amines containing an even number of carbon atoms in the alkyl group thereof are particularly advantageous. They yield excellent rust inhibitors when reacted with the said acid phosphate esters. Further, they are readily available as commercial materials. advantageous class of primary fatty amines may be represented by the following formula:

rimm wmnr-cna wherein n is an even number between 6 and 18. This generic class includes the following members:

Mono-capryl amineCHa(CHz) aCI-IaNHz Mono-lauryl amineCHa(CH-z) 10CH2NH2 Mono-myristyl amine-CI-Is(CI-I2) izCH2NI-l2 Mono-palmityl amine-CH3(CH2)14CH2NH2 Mono-stearyl amineCH3(CH2) 16CH2NH2 Any of the above amines yield advantageous rust inhibitors when reacted with the said acid phosphate esters as described ante.

That is, sometimes we prepare the rust inphosphate ester with some particular one of these amines, but more usually mixtures of fatty amines of this group are employed as they afford a somewhat better product than if only one amine is used. One commercially available mixture, which we ordinarily employ, is the so-called cocoamine made in lmown ways by conversion of cocoanutoil fatty ThisBO 4 acids into corresponding amines. Cocoamine contains a major amount of mono-lauryl amine (the C12 amine) with minor amounts of its adjacent homologues. The average molecular weight of cocoamine ranges between 200 and 210. .A value within this range is considered as the molar weight in reacting cocoamine with the acid phosphate ester.

The other reactant, the acid phosphate esters, are acid phosphate di-esters of di-alkylated phenols, and may be represented by the following generic formula:

wherein R represents a branched chain alkyl group, such as tertiary butyl, secondary butyl, tertiary amyl, di-isobutyl, and like tertiary and secondary alkyl groups, and R represents an alkyl group, advantageously a branched chain alkyl group,

butyl and the like. Thus, the acid phosphate diesters of di-alkylated phenols containing one or two branched chain alkyl groups are especially advantageous in the practice of this invention, particularly those containing two branched chain butyl groups, preferably tertiary butyl groups.

These acid phosphate esters may be prepared by various methods from alkylated phenol containing one or more branched chain alkyl groups attached to the phenyl nucleus in the positions indicated ante.

In particular, the acid phosphate di-estei-s of 2-tertiary-butyl-4-secondary butyl phenol, 2,4- ditertiary-butyl phenol, 2,4-ditertiary-amy1 phenol, and Z-tertiary-butyl-4-tertiary amyl phenol are advantageous for the present purposes. For instance, as shown in the illustrative examples post, di-(2,4-ditertiary-buty1 phenyl) phosphate having the following formula:

solutions of these acid phosphate esters may be employed in preparing concentrates of our rust inhibitors in oil; the amine being added to such all solutions and reacted with the acid phosphate ester dissolved thereinto form the rust inhibitor in situ in the oil. In general, acid phosphate diesters of alkylated phenols containing tertiary or secondary alkyl groups are useful and advantageous in preparing our rust inhibitors; those containing a plurality of such tertiary or secondary alkyl groups being particularly advantageous for the present purposes. Such acid phosphate di-esters are readily soluble in mineral oils and have other properties rendering them' advantageous for the purposes of this invention.

As a class, these acid phosphate di-esters of alkylated phenols containing branched chain alkyl groups react readily with primary fatty amines. In general, the reaction is exothermic and is quite vi orous in most cases. In preparin our rust insuch as secondary .butyl, tertiary hibitors, the reaction temperature is controlled by suitable means to secure smooth reaction and obtain addition products of the amine and acid phosphate esters. In doing so, the temperature of the reaction mixture is controlled by cooling or heating as required; the temperature of the reaction mixture being maintained below 180 F.. to avoid splitting out water from the mixture. The reaction temperature is usually maintained between 140 and 170 F. during the larger portion of the reaction and within this range excellent rust inhibitors are obtained; the pH value of the reaction products being adjusted in the final stages of the reaction to within the desired range stated ante.

The following examples illustrate advantageous methods of preparing these rust inhibitors:

Example I.Into a suitable kettle, equipped' with means for heating, cooling and agitating the charge, there were added 474 pounds of di-(2,4- ditertiary-butyl-phenyl) phosphate, and then 185 pounds of primary dodecyl amine (mon'o-lauryl amine) were gradually added with stirring. The reaction was vigorous and exothermic, and the amine was added at such a gradual rate as to facilitate maintaining the reaction temperature below 180 F.; the mixture being cooled if necessary to maintain it below that temperature. In this way, the reaction temperature was maintained between 140 and 170 F. during the larger part of the reaction. By so controlling the temperature, the side reactions are checked, particularly the splitting out of water from the addition product and conversion of it into the corresponding amide.

After the exothermic reaction had subsided, a further 18 pounds of dodecyl amine were added to the warm reaction mixture and this mixture stirred until the reaction was complete.

The substantially neutral addition product so obtained was a heavy, viscous. oily liquid when cooled to room temperature} It had a pH value of approximately 6.8. This amine salt or rust inhibitor had a pleasant odor and a light amber red color. It was soluble in mineral oils and other hydrocarbons. It is an excellent rust inhibitor for the present purposes.

Similar viscous, oily rust inhibitors can be readily obtained, having pH values within the range of 5.5 and 7.5 by the method described ante. For instance, our oily rust inhibitors can also be prepared from other primary fatty amines and other acid phosphate (ii-esters of alkyl phenols, as well as from the particular amine and acid phosphate ester employed in Example I. The preparation of another such advantageous rust inhibitor is illustrated in the following example. j

Example II.--Here again, the reaction is carried out in a suitable kettle, equipped with means for heating, cooling and agitating the mixture, and the reaction temperature is controlled as described in Example I ante.

Into such a kettle, there were introduced 474 pounds of di-(Z-tertiary butyl-4-sec'ondary butyl phenyl) phosphate, and then 185 pounds of primary dodecyl amine were gradually added with stirring. The reaction was vigorous and quite exothermic and the amine was added at such a gradual rate as to maintain the reaction temperature below 180 F.; .the temperature being maintained between 140 and 170 F., as described in Example I.

After the exothermicreaction had subsided, a

further 20 pounds of dodecyl amine were added.

6 to the warm reaction'mixture and this mixture stirred until thereaction was complete.

The dodecyl amine salt so obtained had a. pH value of approximately 7.2; this salt being a sub-' stantially neutraladdition product of said amine and said acid phosphate di-ester. This salt may be represented-bythe following formula:

II I I r Qw O OH:

in mineral oils. Accordingly, we sometimes prepare concentrated solutions of these rust inhibitors in mineral oil by forming them in situ in the oil. -In such processes, the primary fatty amine is first dissolved in themineral oil and then the acid phosphate ester added, the mixture being stirred and maintained at the desired temperature, until the reaction is complete and the mixture has a pH value within the specified range. In preparing such oil concentrates of our rust inhibitors, sometimes additional amine is'added in the later stages to adjust the pH value as desired. The concentrates or oil solutions of inhibitor reaction products so obtained are useful addition agents to various types of lubricants. The preparation of such concentrates is illustrated in the following example. v

Example III.-Into a suitable kettle, equipped with means for heating, cooling and agitating the charge. there were charged 817 pounds-of light mineral lubricating oil having a viscosity of 100 n seconds, S. U. V. at 100 F., and then 210 pounds of coco amine were added to the oil and thoroughly mixed therewith by stirring: the final temperature of the mixture bein 82 F. Next, while continuing the agitation, 474 pounds of di-(2,4- ditertiary-butyl-phenyl) acid phosphate. were gradually added to the solution of said amine in the oil, over a period of two hours; the perature of the reaction mixture being approximately 178 I. when all the amine had been added. Then the reaction mixture was maintained at said temperature for an additional hour.

Finally, a further 21 pounds of dodecyl amine.

were added to the warm mixture and the resuitant mixture stirred until the reaction was complete, and the oil solution of addition products so obtained had a pH of 7.2. I

The oily mixture prepared inthis Example III can be regarded as a sort of concentrated stock.

' solution which can be stored indefinitely and incorporated' in lubricating oil as desired to pare commercial anti-rust oils, etc.

In general, the rust inhibitors or reaction productsprepared as described ante. may be dissolved in various types of mineral oils and improved anti-rust and non-corrosive oil compositions obtained which are capable .ofinhibiting or retarding the rusting or corrosion of various metals as described- The properties of suchim-.

pre-

proved mineral oil compositions is illustrated in Improved lubricant Properties Base oil Ex. IV Ex. V

Gravity, API 29. 2 28. 7 28. 8 Viscosity. SUV, 100 102 102 103 Flash, 00, F 330 320 330 Fire, 00, 365 300 365 Pour, -30 30 30 Color, Saybolt +7 +5 Carbon residue, per cent. Trace 0. 01 0. Q1 Neutralization No Nil Nil These improved oils had excellent lubricating properties. They also effectively protected steel and other metals against rusting and corrosion.

In fact, the improved oil compositions of Examples IV and V, when tested for non-rusting properties by the various accelerated corrosion tests described post, gave excellent results as compared with the base oil. For instance, in special corrosion Test No. l, the base oil began to show rust on a steel strip after six hours in the test, whereas after twelve days the improved oil showed no evidence of rust. In the other and more drastic corrosion tests described post, these improved oils showed even greater superiority over the base oil as regards protecting steel and other metals against tarnish and corrosion. The results of these special corrosion tests are ummarized in the following table.

The special corrosion tests referred to in the above table were as follows:

Test N0. 1.-36 cc. of the oil or oil composition to be tested and 4 cc. of distilled water are put in a, 1" by 6" Pyrex test tube and a polished strip of copper or steel is immersed in the liquids. To mix the oil and. water, 2000 cc. of air per hour are bubbled through the mixture from a point within the bottom of the test tube. The apparatus is set in a water bath maintained at 122 F. (59 C.) andthe original water level in the tube is maintained by additions of fresh water over 24 hours. The test is continued for twelve day regardless of whether or not the metal strip showed signs of corrosion. This test may also be carried out with other metal strips such as zinc and tin as well as with' copper or steel strips.

In this test, the lower part of the metal strip is completely immersed in the water and the only way the oil can Wet the metal surface is for the oil to creep down over-it against the Water pressure. Accordingly, rusting immediately begins at the level where the oil and the water meet, unless the metal surface is preferentially wetted by the oil; that is, unless the oil film is capable of spreading on the metal surface and displacing water therefrom.

In other words, this test is a rather drastic one for the protective properties of oils and oil compositions as regards the prevention of rust, tarnish and corrosion. For instance, in this test, ordinarily a steel strip'shows rust in about 6 hours and a copper strip will tarnish within approximately 12 hours when an uninhibited oil is so tested. On the other hand, generally the addition of as little as 0.1 per cent by weight of our rust inhibitors to the oil will maintain both copper and steel strips free from tarnish and rust for periods up to 12 days, a maximum duration of this test.

Test No. 2.-In this test, cc. of the oil or oil'composition to be tested and 20 cc. of distilled water are placed in a 400 cc. beaker, and a polished metal strip is immersed in the oil-water mixture; 2000 cc. of humidified air per hour are passed through the mixture and the apparatus is maintained at 122 F. as in Test No. 1. The water level is maintained by daily additions of distilled water and at the end of 12 days the water layer is removed by syphon and fresh water is added. The water removed is analyzed to determine whether the inhibitor is being extracted or leached from the oil solution. Fresh strips are added when the water is changed, so

as to present a fresh metal surface to the partially leached oil. This cycle is continued for '72 days unless the test specimen becomes too corroded, making further testing impractical. In this test, the test specimens are usually steel, copper, tin, silver and zinc, although other special tests may be used.

Test No. 3.--The apparatus outlined in Test No. 1 is employed and the testing conditions are identical, except that water containing sodium chloride in the concentration equivalent to that of the total salt content of sea water is added instead of distilled water. This is a much more severe test and is conducted also for 12 days, the water level being maintained in the same manner as for Test No. 1.

In general, the special corrosion tests described ante are drastic tests of the rust preventive properties of oil compositions. In these tests, the strip of steel or other metal is subjected to attack by moisture and air under extremely severe conditions particularly in Test No. Further, the oil film on the metal and the oil itself are exposed to not only the leaching action of the water but also to oxidation. Accordingly, if rusting is prevented under such drastic conditions in these tests, there is good assurance that the inhibitor will be capable of preventing, or at least retarding rusting .even under extremely severe service conditions. Therefore, an inhibitor which, when dissolved in an oil. permits the oil to pass all three of these tests is considered an excellent inhibitor.

As shown ante, improved oil compositions containing our rust inhibitors have successfully passed all of these tests. Further, our improved oil compositions in addition to having excellent anti-rust properties are also excellent lubricants. Likewise, as shown ante, the anti-rust properties of the improved oil may be controlled by selecting the rust inhibitor and varying the proportions thereof incorporated in the oil. For instance, in certain special cases, where the prevailing conditions are so extreme as to require the lubricant to be extremely highly protective toward metal surfaces, 2. higher percentage of rust inhibitor is incorporated in the oil. The following example is illustrative of such embodiments of this invention.

Example VI.In preparing one such lubricant, 0.3 per cent by weight of the rust inhibitor: obtained in Example I was incorporated in a suitable oil base. The oil base selected and the improved lubricant made from it have the following properties:

Base oil I Improved oil Gravity, API 28. 28. 4 ViSOOSitY, SUV, 100 F 110 109 Color, N PA l. 25 l. 25

This improved oil is capable of preventing rusting and corrosion of metals under extreme conditions, even in the presence of salt and salt water. For instance, when tested by the special corrosion Tests Nos. 1 and 3 ante, the improved oil showed no evidence of corroding either copper or steel after 12 days in either of the above tests. On the other hand, the base oil allowed the steel strip to rust in approximately 8 hours in the fresh water (Test No. 1) and in about 3 hours in the salt water test (Test No. 3). Also, with the base oil, the copper strips were coated with a greenish deposit after overnight testing; the copper strips being more slowly attacked than the steel strips but nevertheless substantially tarnished and corroded.

The specific embodiments described above are merely illustrative of the practice of this invention and other embodiments thereof may be used as desired; for instance, these rust inhibitors are compatible with various other compounding ingredients and they may be added to blended oil bases or compounded lubricants to obtain other types of improved lubricants. Improved oil compositions can be prepared from base oils-containing v rying amounts of fatty oils admixed with mineral oil, such blends being especially'useful as household lubricants. By the presentv invention, any of the previously known household or other lubricants containing relatively light lubrieating oils can be improved by adding small amounts of our rust inhibitors as described.

The invention is equally applicable to heavy mineral oils, petrolatum oils, greases, and jellies; in fact to any petroleum lubricant or coating oil, in which corrosion-preventive properties aredesired. In the claims the term lubricant includes mineral oils, jellies and the like even when used for purposes other than strict lubrication; e. g. 'slushing oils and gun greases.

One important application of the present invention is the prevention of rusting in automotive and aviation engines before or after these have been used, either upon aging or intermittent actual service or in storage of engines or planes of assembly, shipment, and engine break-in. Such rusting the presence in the crankcase of moisture, sulfur, oxidation awaiting completion other delays after is aggravated by and crankcase-oil 1o products from petroleum, tetraethyl lead, decomposition products, etc. Attempts have been made to remedy this condition by washing out all motor oil from the crankcase of an engine if it is to be stored for any appreciable time, or adding compounds containing large amounts of oiliness agents and the like. The present invention presents a more economical remedy for these conditions, for corrosion is effectively retarded under such conditions when from 0.5 to 1.0 per cent by weight of our compounds is added to a motor oil. Adding the highly potent rust preventive compound during the latter part of the break-in period for the new engine, with operation for suflicient time after addition to assure full mixing and coating of parts, will prevent rusting.

Extensive tests in which the pH values of the agents of the present invention as employed in finished oils were varied, confirm our discovery that the optimum results for a given amount of the agent in oil are secured when the pH value is maintained within the stated range of 5.5 to 7.5 for the compounding agent. There is usually a slight drop in pH value in the dilute finished oil solution as compared with the values for the ing of steel surfaces by our steel strip corrosion test, while compositions with an excessively high pH value (alkaline side) may produce greenish corrosion eifects in the cprroslon tests with cop- 1 per surfaces and the like, although not affecting steel to any appreciable extent. The exact adjustment is attained in preparing the rust inhibitor compound by reacting the desired molecular proportions of the two agents in the manner described, and after the pounding reaction has progressed practically to completion by testing the reaction product, and

making any minor adjustments that are necessary for exact control by adding the required small additional proportion of theamines (if on the acid side, of our desired range) or of the acid phosphate ester (if the alkaline side). In measurlng the pH of the anti-rust agents of the present invention and oils containing the which are both substantially water-insoluble, the sample is dissolved in normal butanol (which contains a small amount of water) adjusted'exactly to pHv 7.0. The butanol acts as a blending agent for the water and the relatively insoluble material, but' does not appreciably alter the pH valueas it is of pH exactly 7 itself. Measurement is made by electrometric or colorimetric procedures; v

the results agree closely.

This application is 'a continuation-in-part of application, Serial No. 504,057, now issued-as venting corrosion' thereof in the presence of molsture and air, comprising a petroleum lubricant containing in solution therein a-small proportion of a substantially neutral addition product of a primary fatty amine c'ontainingfrom 8 to 18 carbon atoms and an acid phosphate dl-ester ofneutralization or com- 11 a di-alkylated' phenol having the following formula:

R R O R OWLOGR wherein n is a number between 6 and 16.

3. The improved oil composition of claim 1 wherein said addition product is a substantially neutral addition 'product of said acid phosphate di-ester and dodecylamine.

4. The improved oil composition of claim 1 wherein said addition product is a substantially neutral addition product of said primary fatty amine and di- (2,4 diptertiary butyl phenyl) phosphate.

5. The improved oil composition of claim 1 wherein said addition product is a substantially neutral addition product of said primary fatty amine and di (2 tertiary butyl 4 secondary butyl-phenyl) phosphate. 1

6. The improved oil composition of claim 1 wherein said addition product is substantially neutral addition product of dodecylamine and di- (2,4-di-tertiary-butyl-phenyl) phosphate, said addition product having a pH value of 7.2.

'7. The improved oil composition of claim 1 wherein said petroleum lubricant contains from 0.01 to 10.0 per cent by weight of said substantially neutral addition product dissolved therein.

8. An improved oil composition, effective as'a lubricant for ferrous and other metalsurfaces and capable of preventing corrosion thereofin the presence of moisture and air, comprising a mineral lubricating oil and 0.01 to 10.0 per cent by weight on the oil of a substantially neutral addition product of a primary fatty amine containing from 8 to 18 carbon'atoms and an acid phosphate di-ester of di-alkylated phenols' having the following formula:

wherein R represents a branched chain alkyl group and R represents an alkyl group, said substantially neutral addition product having a pH between 5.5 and 7.5 and the proportion thereof dissolved in the lubricant being suflicient to prevent rusting of ferrous metals.

9. The improved oil composition of claim 8 wherein said mineral lubricating oil is a light mineral oil having a Saybolt Universal viscosity between and 150 seconds at F.

'10. The. improved oil composition of claim 8 wherein the addition product is a substantially neutral addition product of dodecylamine and di-(2,4-di-tertiary-butyl-phenyl) phosphate.

11. An improved oil composition, effective as a lubricant for ferrous and other metal surfaces and capable of preventing corrosion thereof in the presence of moisture and air, comprising a light mineral oil of viscosity between 60 and seconds SUV at 00 F. containing and 10.0 per cent of a substantially neutral addition product, of dodecylamine and di-(2,4-ditertiary-butyl-phenyl) phosphate, said addition product having a pH value of 7.2 and the proportion thereof being sufficient to prevent rusting of ferrous metals.

HERSCI-IEL G. SMITH. TROY L. CAN'I'REIL.

between 0.01 

